Citations

Abstract OBJECTIVE AND IMPORTANCE: Optic nerve choristoma is a rare lesion composed of adipose tissue and smooth muscle involving the optic nerve. Few cases have been reported. CLINICAL PRESENTATION: A 20-year-old woman presented with a history of slowly progressive visual loss in the left eye. On T1-weighted magnetic resonance imaging studies, after frequency-selective fat saturation, an optic nerve mass was detected at the level of the optic canal with signal characteristics suggesting the diagnosis of optic nerve lipoma. INTERVENTION: At left frontotemporal craniotomy, the intracranial optic nerve appeared thin and atrophic proximally and was covered by abundant adipose tissue distally. Because no cleavage plane could be identified between the fatty lesion and the optic nerve, which appeared splayed within the adipose tissue, the nerve was resected after an intraoperative biopsy. The presence of two heterotopic mesodermal elements, a rim of adipose tissue admixed with bundles of mature smooth muscle, extending into the nerve septa, warranted a diagnosis of optic nerve choristoma. CONCLUSION: Optic nerve choristoma is an uncommon optic nerve lesion. Even if imaging studies are highly suggestive of the diagnosis, pathological confirmation is required because of the high adipose tissue content in the majority of cases. The lesion, most likely malformative and nonneoplastic in nature, can be the cause of progressive visual loss.

AbstractOBJECTIVE:The purpose of this study was to describe the natural history of tethered cord in patients who have undergone meningomyelocele repair.METHODS:We performed a retrospective review of 45 patients with a history of neonatal meningomyelocele repair who subsequently developed symptoms of tethered cord. Symptoms of tethered cord in this cohort consisted of the development of bladder spasticity or orthopedic foot deformity. None of these patients were treated with cord untethering; instead, they were treated symptomatically.RESULTS:On follow-up, 40 (88.9%) of these patients subsequently required additional orthopedic or urological procedures because of further symptoms of tethered cord. The incidence of progression of tethered cord syndrome is 27.5, 40, and 60% at 1, 2, and 5 years, respectively.CONCLUSION:Although this study does not address the question whether cord untethering will prevent further symptom development, these results do provide a strong rationale for consideration of an untethering procedure in patients with repaired meningomyelocele at the time of the onset of symptoms of tethered cord.

Abstract OBJECTIVE AND IMPORTANCE A case of acutely symptomatic epidural hematoma caused by metastatic hepatocellular carcinoma (HCC) to the cranium is reported. This is a rare case of metastatic HCC without known primary presenting as an epidural hematoma. CLINICAL PRESENTATION The patient presented with an acute onset of headache, aphasia, and right hemiparesis 2 weeks after he experienced minor trauma to the cranium. An emergency computed tomographic scan of the head revealed the presence of a left parietal epidural hematoma. INTERVENTION An emergency evacuation of the epidural hematoma was performed, and metastatic HCC was diagnosed. CONCLUSION The patient's neurological deficits were reversed with surgical intervention, and he is now undergoing palliative chemotherapy. This was the first clinical manifestation of HCC in this patient. This case reaffirms the neurosurgeon's role in the complex, multidisciplinary care of patients with craniospinal metastasis.

Abstract OBJECTIVE The proper treatment for patients with cyst formation after arteriovenous malformation radiosurgery is unknown. METHODS The treatment of six patients who developed cysts after arteriovenous malformation radiosurgery is described. Four patients had undergone gamma knife radiosurgery (two patients developed cysts after repeat procedures), and two patients had undergone linear accelerator-based radiosurgery. The median prescription isodose volume at the time of the first radiosurgical procedure was 13.2 cm3 (range, 8.0–28.7 cm3). RESULTS The cysts were discovered a median of 48 months (range, 24–89 mo) after radiosurgery. Three patients were originally without symptoms, and observation with serial imaging was performed; two of those patients developed symptoms 13 and 40 months later, whereas one patient has remained without symptoms for 51 months. Initial treatments for patients with symptomatic cysts included cyst aspiration (n = 3) and placement of a cystoperitoneal shunt (CPS) (n = 2). The median cyst volume was 14 cm3 (range, 4–63 cm3). Cyst recurrence occurred within 2 months for patients who underwent aspiration alone, necessitating placement of a CPS. Shunt placement eliminated the cysts for four patients, at a median follow-up time of 16 months (range, 9–27 mo). One patient's cyst persisted despite CPS placement, and cyst excision was performed. No morbidity occurred with any of the cyst treatments. CONCLUSION Cyst formation after arteriovenous malformation radiosurgery may occur many years after the procedure. Although most symptomatic cysts can be effectively treated with CPSs, cyst excision may be necessary if the mass effect is not relieved with the less invasive approach.

Abstract OBJECTIVE To report presenting clinical symptoms, previous medical history, and survival rates for people with saccular intracranial aneurysms (IAs), in a defined population. METHODS The medical records of all residents of Olmsted County, Minnesota, with possible IAs were reviewed. Clinical manifestations at the time of diagnosis, previous medical history, demographic factors, and survival rates after diagnosis were determined. RESULTS Of 270 people with IAs detected between 1965 and 1995, 188 exhibited symptoms at the time of diagnosis, including 74% of women and 63% of men (P = 0.054). Intracranial hemorrhage (ICH) was the most common presenting symptom (60% of all patients and 86% of patients who exhibited symptoms), followed by cranial nerve palsy, transient ischemic attacks, and seizures. Survival rates after detection (with the exclusion of cases that were first detected during autopsies) were dependent on the occurrence of ICH; 23% of patients who presented with ICH died by 1 day after diagnosis, compared with 5% of those who did not exhibit symptoms or exhibited symptoms but without ICH at presentation. At 5 years, 44.7% of patients with hemorrhage had died, compared with 29.4% of patients with symptoms other than hemorrhage. After the first 24 hours after detection, survival rates did not differ significantly for those presenting with or without hemorrhage. Predictors of better survival rates also included lower age and later calendar year of presentation. CONCLUSION This study provides the first data on aneurysm characteristics, clinical symptoms, and survival rates among people with IAs in a defined population. During the study period, most aneurysms were detected in the context of an aneurysm-related symptom (particularly among women), with a large proportion of patients presenting with ICH. After the acute phase of hemorrhage, long-term survival rates among people with IAs were similar for those presenting with or without ICH.

Abstract OBJECTIVE Stereotactic radiosurgery is being used with more frequency in the management of patients with trigeminal neuralgia. To improve facial pain outcomes, many centers have increased the prescribed radiation dose to the trigeminal nerve. METHODS Between April 1997 and December 1999, 68 patients underwent radiosurgery for trigeminal neuralgia with use of the Leksell gamma knife (Elekta Instruments, Norcross, GA) and a single 4-mm isocenter of radiation. Twenty-seven patients (40%) received 70 Gy (low dose) of irradiation and 41 patients (60%) received 90 Gy (high dose). The groups were similar with regard to age, sex, duration of pain, number of prior surgeries, and preexisting trigeminal deficits. The primary facial pain outcomes for analysis were excellent (pain-free, no medications) and good (pain-free, reduced medications). The mean length of follow-up after radiosurgery was 14.4 months (range, 2–36 mo). RESULTS At last follow-up examination, 11 (41%) of the 27 patients with low-dose radiosurgery remained pain-free compared with 25 (61%) of the 41 patients with high-dose radiosurgery (P = 0.17). Additional surgery was performed in 12 low-dose patients (44%) and 8 high-dose patients (20%) (P = 0.05). High-dose radiosurgery was associated with an increased rate of permanent trigeminal nerve dysfunction (54% versus 15%, P = 0.003). Bothersome dysesthesias occurred in 13 high-dose patients (32%), whereas only 1 low-dose patient had this complication (P = 0.01). Three high-dose patients (8%) developed corneal numbness after radiosurgery. Pain recurred with more frequency in patients not developing trigeminal nerve dysfunction after radiosurgery (9 of 22 patients, 41%) compared with those who sustained facial numbness, paresthesias, or dysesthesias (4 of 27 patients, 15%); however, the difference was not statistically significant (P = 0.08). CONCLUSION Higher doses of radiation may correlate with better facial pain outcomes after radiosurgery for trigeminal neuralgia. However, the incidence of significant trigeminal nerve dysfunction is markedly increased after radiosurgery for patients receiving high-dose radiosurgery. Because of the nonselective nature of this ablative technique, dose prescription should be limited to less than 90 Gy.